Kidney Stone Medication, Prevention, Diet (Foods to Avoid)

Most kidney stones pass spontaneously without the need for medical intervention. Stones as large as 3 to 4mm may pass through uninhibited but larger stones may result in obstructions. Increasing fluid intake to push out the stone is essential. If the pain is severe, analgesics may be necessary. These measures may be all that is needed to manage the pain while the urinary system passes out the kidney stone. In certain cases, other treatment options maybe necessary to remove the stone.

Medication for Kidney Stones

  • Analgesics. Tablets or suppositories are usually prescribed for the pain but if necessary IV (intravenous) administration or an intramuscular injection  may be a better option. Many NSAID’s (non-steroidal anti-inflammatory drugs) can be purchased without a prescription. Stronger pain relieving drugs like opioids may be needed for severe kidney stone pain.
  • Antibiotics may be required if there is an infection, especially in a case of struvite stones.
  • Corticosteroids may be prescribed to ease the inflammation of the urinary tract. Inflammation results in swelling of the ureteral walls and narrowing of the lumen. By reducing the inflammation, the stone can pass through.
  • Smooth muscle relaxants like like alpha blockers and calcium channel blockers help to relax the smooth muscle of the ureters. This expands the ureteral lumen and allows the stone to pass with less resistance.
  • Diuretics, particularly thiazide diuretics, reduce calcium excretion (calcium stones). These drugs also help increase urine output. *
  • Allopurinol may be used for short periods to reduce uric acid levels in the blood and urine. This is useful for uric acid stones but hyperuricosuria (high uric acid levels in the urine) should first be confirmed. *
  • Supplements and binding agents. Vitamin B6 (pyridoxine) may help decrease oxalate production within the body while calcium supplements will bind oxalate in the gut. This is helpful for calcium oxalate stones. Chelating agents like penicillamine help to bind cystine (cystine stones).
  • Alkalizing agents are helpful in preventing the urine from becoming too acidic. This is useful for uric acid stones as a urine pH greater than 6 makes it more soluble. Sodium bicarbonate may be used but this can increase sodium in the urine (hypernatriuria) which should be avoided. Potassium citrate may be a better option for alkalizing the urine.

* Loop diuretics and long term use of  allopurinol should be avoided in recurrent cases of certain types of kidney stones. Discuss this with your doctor.

Kidney Stone Prevention

For patients prone to recurrent kidney stones, dietary prevention can be effective if no other chronic conditions are contributing to the presence of kidney stones (nephrolithiasis). Certain foods and drugs may contribute towards preventing kidney stones but it is important to first consult with your doctor to confirm/exclude other contributing factors.

Calcium and Kidney Stones

Contrary to popular belief, a normal calcium intake may play a role in preventing kidney stones. While calcium oxalate stones are by far the most common type of kidney stone, it is the high oxalate output that is one of the predisposing factors for kidney stones. Calcium binds with oxalate in the gastrointestinal tract thereby lowering the absorption and excretion.

A normal calcium diet does not mean that the calcium level in the blood will be high. The body regulates the calcium levels in the blood but in certain conditions, this may be disrupted thereby leading to hypercalcemia (high calcium levels in the blood) even if the dietary calcium intake is low. Any cause of hypercalcemia or hypercalciuria (high calcium levels in the urine) may increase the risk of developing kidney stones. This should not be confused with dietary calcium and a diet low in calcium may result in the formation of oxalate stones.

Unused calcium is passed out of the body through the urine. It can combine with a number of other substances and waste products, like oxalate, to form kidney stones. Even in normal amounts, calcium in the urine may form kidney stones by binding to other substances.

Kidney Stones Diet

Water Intake

Fluid intake is important for the prevention of kidney stones. Water is the best option and any person who is at risk of developing kidney stones should consume 2 to 4 litres of water a day. Avoid drinks that may contribute to dehydration like coffee, alcohol and caffeinated soft drinks. The fluid intake should be spread out during the course of the day.

List of Foods to Avoid

Most kidney stones are calcium oxalate stones (75% to 80%). Struvite stones (10% to 15%) are a result of repeated infections which affect the pH of the urine – dietary changes are insignificant in preventing the formation of these stones. Uric acid stones constitute some 5% of kidney stone cases and dietary changes can be beneficial for preventing the formation of these stones.

Calcium Oxalate Stones

Reducing the intake of foods rich in oxalate is essential in preventing these types of kidney stones. Spinach and rhubarb are two vegetables that are very high in oxalate compared to other foods.

Other foods include :
Vegetables, Fruits and Grains

  • Beans
  • Beets
  • Berries
  • Celery
  • Grapes
  • Green pepper
  • Okra
  • Peanuts
  • Red raspberries
  • Strawberries
  • Sweet potatoes
  • Swiss chard
  • Wheat bran
  • Wheat germ

High meat intake should be avoided. This includes red and white meat and fish. Offals (example : liver) should be avoided altogether.

Processed and Prepared Foods

  • Bran muffins, cereals
  • Chocolate
  • Cakes with fruit
  • Grits
  • Marmalade
  • Peanut butter
  • Soybean foods


  • Alcohol
  • Coffee
  • Cola drinks
  • Certain energy drinks
  • Tea


  • Vitamin D supplements should be avoided as it increases calcium absorption.
  • High intake of vitamin C supplements (mega doses) increases oxalate excretion through the kidneys.

Uric Acid Stones

Many of the dietary changes for the prevention of calcium oxalate stones may also be helpful for uric acid stones.

  • Alcohol should be avoided.
  • Caffeinated drinks should be limited.
  • Legumes like lentils should be limited or avoided altogether.
  • Meat intake, especially offals, should be reduced.
  • Dairy intake should be moderate.

Any dietary supplement that can make urine more alkaline like sodium bicarbonate may be helpful for uric acid stones as they are more soluble at a pH levels higher than 6.

 Last updated on August 14, 2018.

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